It is known to mount motor vehicle seats on running rails on both outer sides so that the position of the seats can be changed stepwise in the direction of the longitudinal axis of the vehicle.
However, these known designs are very expensive, are heavy, and are not particularly strong, especially in respect of ability to withstand the loads arising in a crash without breaking. They are sensitive to jamming, which however cannot always be avoided in the case of such parts made without the use of machining, and the tolerances of the points of attachment also leave much to be desired.
Thus in the case of a seat rail according to German patent 32 26 585 the two associated profiled rods are made by fitting together two pairs of sections, and only rollers are used for rolling bearings to take the downward loading. This leads to high cost and also to the condition of high sliding friction arising when there is upward loading. This often comes about as a result of the moment that arises when the support occurs in the front or rear region of the guide means as a result of forces acting high up due to the person seated leaning back against or pulling on the backrest. There is then no rolling bearing action, and consequently the adjustment is stiff, above all if lateral forces have to be withstood as well.
The object of the invention is to provide a running rail of the kind referred to having a lower rail part and an associated upper rail part of lightweight construction, that offer high stability, easy running properties and insensitivity to tilting and consequently problem-free mounting.
The advantages obtained with the invention are essentially that in a running rail for motor vehicle seats full rolling bearing support is provided for the loading acting upwardly, downwardly and also in directions inclined thereto, and that the upper and lower rail parts provide mutual support in their upper regions in the case of high loadings, so that the tendency to gape apart is countered at low cost.
An exemplary embodiment of the invention is illustrated in the drawings and will now be described in more detail.